To substantially increase the vertical stiffness and reduce the vertical residual compression of geotextile-reinforced soil (GRS) structures subjected to long-term traffic load, the preloading and prestressing (PLPS) method has been proposed. The seismic stability of PLPS GRS structures was investigated hy performing shaking table model tests using sinusoidal waves with horizontal acceleration of 700 gals. The use of a newly developed device, called the ratchet system, is very effective in increasing the seismic stability of the structures by maintaining high prestress when the backfill tends to contract and preventing the expansion of the backfill. These functions effectively prevent the occurrence of resonant state while restraining the bending deformation of the structure, which are essential for the high seismic stability of the structure. For the covering abstract see ITRD E125786.